Generally an offset printing machine includes, as shown in FIG. 9, three cylinders, a plate cylinder 51, a blanket cylinder 52 and an impression cylinder 53 which are arranged with the axial lines being parallel with each other and are capable of contacting to each other. A press plate (not shown) of zinc or aluminium is wound on the plate cylinder 51, and the rubber blanket is wound on the blanket cylinder 52.
The press plate is supplied with water by a dampening arrangement 54 to keep the non image area of the press plate except the printing image thereof wet, and an oily ink is applied to the surface of the press plate by an inking arrangement 55.
As shown in FIG. 10, the inking arrangement 55 has an ink roller train mechanism for applying ink evenly to the surface of the press plate.
The ink roller train mechanism comprises a metal link fountain roller 60 for taking ink out of an ink fountain, an ink ductor 61 for receiving the ink from the ink fountain roller, a metal reciprocating ink roller 62 contacting the ink ductor for receiving the ink therefrom, downstream metal reciprocating ink rollers 54 for receiving the ink from the reciprocating ink roller through ink distributing rollers 63, and form rollers 55 for applying the ink from the downstream reciprocating ink rollers 54 to the surface of the press plate.
In this ink roller train mechanism the ink conducted from the ink fountain 59 is spread evenly on the surfaces of the ink roller train by the plural metal reciprocating rollers arranged through the intermediary of the elastic rollers to be applied evenly to the surface of the plate cylinder by the form rollers.
In the offset printing machines, the ink roller train are cleaned when a printing color is changed or during a pause of a printing operation. This cleaning operation is performed with the ink roller train set on idling after first the form roller 65 and the surface of the press plate, and the ink ductor 51 and the reciprocating ink roller 52 are set apart from each other respectively, and the supply and application of the ink to the plate cylinder are stopped.
Conventionally, the cleaning of the ink roller train are performed largely by two methods. In a first method, a cleaning oil, or a solvent, e.g., kerosene, linseed oil, or others, is sprinkled on the idling ink rollers, and when it is confirmed that the solvent has been distributed all over the respective ink roller train and sufficiently softened ink on the ink roller train, the ink is removed by a knife, and next the ink still remaining on the ink roller train is wiped off by cloths. This is theso-called completely manual operation.
A second cleaning method uses a manually operable ink cleaning device 66- This ink cleaning device 66 comprises an ink pan 68 detachably attached to a support 67 secured to the side frame of the offset printing machine movably back and forth in the direction perpendicular to the shafts of the ink roller train, and a doctor blade 69 attached to the ink pan on the side nearer to the ink roller train, opposed to the ink roller train so as to scrape the ink 71 on the surface of the ink roller train. In the cleaning operation, first the ink pan 68 is set, a solvent is sprinkled on the surfaces of the idling ink rollers, and the ink roller train are set on idling until the solvent is distributed all over the respective ink roller train. Then a handle 70 is operated to move the ink pan forward to abut on the surface of the ink roller train, and the ink 71 is scraped off the surface of the ink roller train into the ink pan. At this time, because of the property that the ink 71 on the ink roller train flows from a higher concentration to a lower concentration, the ink on the ink roller train other than the ink roller with the doctor blade abutted on flows to the ink roller train to be scraped off there. The ink pan is detached from the support 67 for the disposal of the waste oil containing the ink, the solvent, etc. collected therein.
But, the first cleaning method is the so-called manual operation in which the ink staying on the surfaces of the ink roller train is removed by means of a knife, and the still remaining ink is wiped off by hands using cloths impregnated with a solvent. When the ink roller train mechanism has multi-stages of ink roller train, the first cleaning method takes time to clean each of the ink roller train, and smears operators' bodies, e.g., hands. These are reasons why the first method has been disliked. In the second cleaning method, since hands do not directly touch the ink roller train in the cleaning operation, operators' bodies are not smeared with the ink, but the disposal of the ink scraped off the ink roller train and collected in the ink pan is bothering. The ink pan which has been emptied of the waste oil is cleaned for the next ink roller train cleaning operation. Since cloths and a solvent are used to clean the ink pan, operators' hands are smeared, and besides, this ink pan cleaning has to be repeated for the cleaning of each ink roller train, which is very bothering to the operators.
In addition, the unwoven cloth used in the conventional blanket cleaning or the cleaning cloth for the manual wipe do not have such high oil absorbency that a large quantity of the material is required for the cleaning. Accordingly to experiments, when a used amount of a solvent was around 200 cc/time per 1 unit of A1 size machine, 1 meter of unwoven fabric was used.
A first object of this invention is to provide a method for cleaning an ink roller train which can cause ink remaining on the ink roller train to automatically permeate a web or a sheet of cleaning cloth to be held by the same, and disposes of the cleaning cloth.
A second object of this invention is to provide a method for cleaning an ink roller train which can cause ink remaining on the ink roller train to automatically permeate a web or a sheet of cleaning cloth to be held by the same, and disposes the cleaning cloth in such a manner as not to leak out the ink.
A third object of this invention is to provide a device for cleaning an ink roller train for use in printing machines which can cause ink remaining on the ink roller train to automatically permeate a cleaning cloth to be held by the same.
A fourth object of this invention is to provide a device for cleaning an ink roller train for use in printing machines which can cause the ink scraped off by a doctor blade to automatically permeate a sheet of cleaning cloth to be held by the same.
A fifth object of this invention is to provide a device for cleaning an ink roller train which comprises means for forcing a web or a sheet of cleaning cloth to hold the ink it has absorbed.